Stacked, disk-type lenticular filters have been used in processing of fluids for commercial applications. In a typical filtration system employing such filters, the filters are assembled for operation inside a sanitary housing that is sealable from an ambient environment. Each disk-type filter comprises an outer ring and an inner core. The outer ring and inner core are connected by a web of filtration media of some type, and the filtration media is sealed to the outer ring and the inner core. The disk-type filter is typically designed to accommodate fluid flow from outside to in. In other words, fluid to be filtered typically flows into the sanitary housing, through the filtration media, and into the inner core. Typically, several such disk-type filters are stacked upon one another, forming a stacked inner core extending along the axis of each disk. The housing is typically a generally cylindrical pressure vessel that has structure for fluid ingress and egress.
In typical systems, it is important that each filter remain properly sealed to each adjacent filter during operation, so as to prevent bypass of fluid past the filtration media. To that end, the stack of filters is typically held together, or compressed, at least partly through the use of a center rod. The center rod is typically a continuous rod extending through the stacked inner core. The center rod can comprise or be accompanied by one or more means for providing compression to the stack of filters, including an “active follower.” An active follower may employ a resilient spring to help “take up” any slack or looseness that may develop in the stack after the filtration media becomes wetted and more readily crushes. Proper compression of the stack can be a matter of “feel” and is often dependent upon the skill and training of the operator.
Under normal operation, pressurized fluid to be filtered enters the sanitary housing through the fluid ingress and fills the area surrounding the disk-type lenticular filters. The fluid is then filtered through the filter elements, after which the filtered fluid enters the stacked inner core. The stacked inner core is fluidly connected to a fluid egress, which can route the filtered fluid (filtrate) to downstream plumbing.
Such systems are often bulky and time consuming to assemble. Furthermore, such systems typically comprise several heavy and expensive metallic parts that must be cleaned and sanitized between uses. The sanitary housing must be carefully cleaned with each use. The sanitizing steps can add significant delay to processes. Often, significant quantities of sanitizing agent must be used to sanitize such parts. Consumption and disposal of such sanitizing agents can create undesirable environmental impact. Furthermore, such systems often require a skilled and trained operator for proper compression.
There is a continuing need for filtration systems that are lighter and are easier to assemble. There is also a need for filtration systems employing materials that, when disposed of, are less expensive and more environmentally friendly. There is also a need for filtration systems that require less cleaning and down-time between uses. There is also a need for filtration systems that are less reliant upon operator skill in achieving satisfactory results.